notes.husk.org/likes images.

Spotted in the Union Pacific rail yard - Milford, UT

Behold, the mighty Plasser & Theurer EM120-EC-4

Track geometry recording cars made by Plasser & Theurer supply a wealth of information, depending on their equipment and the requirements. Apart from data on the track geometry, this also includes data on the rail profile, wear of the running edge, rail inclination and surface faults of the rails. Modern measuring systems are capable of measuring the clearance gauge and the ballast profile, monitoring the rail fastenings, video inspection and measuring the position of the contact wire.

Catch it in action:  http://www.plassertheurer.com/en/machines-systems/measuring-work-em-sat-120.html